linux/sound/core/pcm_memory.c
Takashi Iwai 6ab08ced64 ALSA: PCM: Warn when buffer preallocation fails
The failures of buffer preallocations at driver initializations aren't
critical but it's still helpful to inform, so that user can know that
something doesn't work as expected.

For example, the recent page allocator change triggered regressions,
but developers didn't notice until recently because the driver didn't
complain.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-01-11 11:04:23 +01:00

461 lines
14 KiB
C

/*
* Digital Audio (PCM) abstract layer
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <asm/io.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/moduleparam.h>
#include <linux/vmalloc.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/info.h>
#include <sound/initval.h>
static int preallocate_dma = 1;
module_param(preallocate_dma, int, 0444);
MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
static int maximum_substreams = 4;
module_param(maximum_substreams, int, 0444);
MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
static const size_t snd_minimum_buffer = 16384;
/*
* try to allocate as the large pages as possible.
* stores the resultant memory size in *res_size.
*
* the minimum size is snd_minimum_buffer. it should be power of 2.
*/
static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)
{
struct snd_dma_buffer *dmab = &substream->dma_buffer;
size_t orig_size = size;
int err;
do {
if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,
size, dmab)) < 0) {
if (err != -ENOMEM)
return err; /* fatal error */
} else
return 0;
size >>= 1;
} while (size >= snd_minimum_buffer);
dmab->bytes = 0; /* tell error */
pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
substream->pcm->card->number, substream->pcm->device,
substream->stream ? 'c' : 'p', substream->number,
substream->pcm->name, orig_size);
return 0;
}
/*
* release the preallocated buffer if not yet done.
*/
static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
{
if (substream->dma_buffer.area == NULL)
return;
snd_dma_free_pages(&substream->dma_buffer);
substream->dma_buffer.area = NULL;
}
/**
* snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
* @substream: the pcm substream instance
*
* Releases the pre-allocated buffer of the given substream.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
{
snd_pcm_lib_preallocate_dma_free(substream);
#ifdef CONFIG_SND_VERBOSE_PROCFS
snd_info_free_entry(substream->proc_prealloc_max_entry);
substream->proc_prealloc_max_entry = NULL;
snd_info_free_entry(substream->proc_prealloc_entry);
substream->proc_prealloc_entry = NULL;
#endif
return 0;
}
/**
* snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
* @pcm: the pcm instance
*
* Releases all the pre-allocated buffers on the given pcm.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
{
struct snd_pcm_substream *substream;
int stream;
for (stream = 0; stream < 2; stream++)
for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
snd_pcm_lib_preallocate_free(substream);
return 0;
}
EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
#ifdef CONFIG_SND_VERBOSE_PROCFS
/*
* read callback for prealloc proc file
*
* prints the current allocated size in kB.
*/
static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_pcm_substream *substream = entry->private_data;
snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
}
/*
* read callback for prealloc_max proc file
*
* prints the maximum allowed size in kB.
*/
static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_pcm_substream *substream = entry->private_data;
snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
}
/*
* write callback for prealloc proc file
*
* accepts the preallocation size in kB.
*/
static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
struct snd_pcm_substream *substream = entry->private_data;
char line[64], str[64];
size_t size;
struct snd_dma_buffer new_dmab;
if (substream->runtime) {
buffer->error = -EBUSY;
return;
}
if (!snd_info_get_line(buffer, line, sizeof(line))) {
snd_info_get_str(str, line, sizeof(str));
size = simple_strtoul(str, NULL, 10) * 1024;
if ((size != 0 && size < 8192) || size > substream->dma_max) {
buffer->error = -EINVAL;
return;
}
if (substream->dma_buffer.bytes == size)
return;
memset(&new_dmab, 0, sizeof(new_dmab));
new_dmab.dev = substream->dma_buffer.dev;
if (size > 0) {
if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
substream->dma_buffer.dev.dev,
size, &new_dmab) < 0) {
buffer->error = -ENOMEM;
return;
}
substream->buffer_bytes_max = size;
} else {
substream->buffer_bytes_max = UINT_MAX;
}
if (substream->dma_buffer.area)
snd_dma_free_pages(&substream->dma_buffer);
substream->dma_buffer = new_dmab;
} else {
buffer->error = -EINVAL;
}
}
static inline void preallocate_info_init(struct snd_pcm_substream *substream)
{
struct snd_info_entry *entry;
if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
entry->mode |= S_IWUSR;
entry->private_data = substream;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
entry = NULL;
}
}
substream->proc_prealloc_entry = entry;
if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
entry->private_data = substream;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
entry = NULL;
}
}
substream->proc_prealloc_max_entry = entry;
}
#else /* !CONFIG_SND_VERBOSE_PROCFS */
#define preallocate_info_init(s)
#endif /* CONFIG_SND_VERBOSE_PROCFS */
/*
* pre-allocate the buffer and create a proc file for the substream
*/
static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
size_t size, size_t max)
{
if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
preallocate_pcm_pages(substream, size);
if (substream->dma_buffer.bytes > 0)
substream->buffer_bytes_max = substream->dma_buffer.bytes;
substream->dma_max = max;
preallocate_info_init(substream);
return 0;
}
/**
* snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
* @substream: the pcm substream instance
* @type: DMA type (SNDRV_DMA_TYPE_*)
* @data: DMA type dependent data
* @size: the requested pre-allocation size in bytes
* @max: the max. allowed pre-allocation size
*
* Do pre-allocation for the given DMA buffer type.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
int type, struct device *data,
size_t size, size_t max)
{
substream->dma_buffer.dev.type = type;
substream->dma_buffer.dev.dev = data;
return snd_pcm_lib_preallocate_pages1(substream, size, max);
}
EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
/**
* snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
* @pcm: the pcm instance
* @type: DMA type (SNDRV_DMA_TYPE_*)
* @data: DMA type dependent data
* @size: the requested pre-allocation size in bytes
* @max: the max. allowed pre-allocation size
*
* Do pre-allocation to all substreams of the given pcm for the
* specified DMA type.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
int type, void *data,
size_t size, size_t max)
{
struct snd_pcm_substream *substream;
int stream, err;
for (stream = 0; stream < 2; stream++)
for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
return err;
return 0;
}
EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
#ifdef CONFIG_SND_DMA_SGBUF
/**
* snd_pcm_sgbuf_ops_page - get the page struct at the given offset
* @substream: the pcm substream instance
* @offset: the buffer offset
*
* Used as the page callback of PCM ops.
*
* Return: The page struct at the given buffer offset. %NULL on failure.
*/
struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
{
struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
unsigned int idx = offset >> PAGE_SHIFT;
if (idx >= (unsigned int)sgbuf->pages)
return NULL;
return sgbuf->page_table[idx];
}
EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
#endif /* CONFIG_SND_DMA_SGBUF */
/**
* snd_pcm_lib_malloc_pages - allocate the DMA buffer
* @substream: the substream to allocate the DMA buffer to
* @size: the requested buffer size in bytes
*
* Allocates the DMA buffer on the BUS type given earlier to
* snd_pcm_lib_preallocate_xxx_pages().
*
* Return: 1 if the buffer is changed, 0 if not changed, or a negative
* code on failure.
*/
int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
{
struct snd_pcm_runtime *runtime;
struct snd_dma_buffer *dmab = NULL;
if (PCM_RUNTIME_CHECK(substream))
return -EINVAL;
if (snd_BUG_ON(substream->dma_buffer.dev.type ==
SNDRV_DMA_TYPE_UNKNOWN))
return -EINVAL;
runtime = substream->runtime;
if (runtime->dma_buffer_p) {
/* perphaps, we might free the large DMA memory region
to save some space here, but the actual solution
costs us less time */
if (runtime->dma_buffer_p->bytes >= size) {
runtime->dma_bytes = size;
return 0; /* ok, do not change */
}
snd_pcm_lib_free_pages(substream);
}
if (substream->dma_buffer.area != NULL &&
substream->dma_buffer.bytes >= size) {
dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
} else {
dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
if (! dmab)
return -ENOMEM;
dmab->dev = substream->dma_buffer.dev;
if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
substream->dma_buffer.dev.dev,
size, dmab) < 0) {
kfree(dmab);
return -ENOMEM;
}
}
snd_pcm_set_runtime_buffer(substream, dmab);
runtime->dma_bytes = size;
return 1; /* area was changed */
}
EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
/**
* snd_pcm_lib_free_pages - release the allocated DMA buffer.
* @substream: the substream to release the DMA buffer
*
* Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime;
if (PCM_RUNTIME_CHECK(substream))
return -EINVAL;
runtime = substream->runtime;
if (runtime->dma_area == NULL)
return 0;
if (runtime->dma_buffer_p != &substream->dma_buffer) {
/* it's a newly allocated buffer. release it now. */
snd_dma_free_pages(runtime->dma_buffer_p);
kfree(runtime->dma_buffer_p);
}
snd_pcm_set_runtime_buffer(substream, NULL);
return 0;
}
EXPORT_SYMBOL(snd_pcm_lib_free_pages);
int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
size_t size, gfp_t gfp_flags)
{
struct snd_pcm_runtime *runtime;
if (PCM_RUNTIME_CHECK(substream))
return -EINVAL;
runtime = substream->runtime;
if (runtime->dma_area) {
if (runtime->dma_bytes >= size)
return 0; /* already large enough */
vfree(runtime->dma_area);
}
runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
if (!runtime->dma_area)
return -ENOMEM;
runtime->dma_bytes = size;
return 1;
}
EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
/**
* snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
* @substream: the substream with a buffer allocated by
* snd_pcm_lib_alloc_vmalloc_buffer()
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime;
if (PCM_RUNTIME_CHECK(substream))
return -EINVAL;
runtime = substream->runtime;
vfree(runtime->dma_area);
runtime->dma_area = NULL;
return 0;
}
EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
/**
* snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
* @substream: the substream with a buffer allocated by
* snd_pcm_lib_alloc_vmalloc_buffer()
* @offset: offset in the buffer
*
* This function is to be used as the page callback in the PCM ops.
*
* Return: The page struct, or %NULL on failure.
*/
struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
unsigned long offset)
{
return vmalloc_to_page(substream->runtime->dma_area + offset);
}
EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);